options:
1: RGB to VGA adapter. If the monitor does NOT support 15 mhz, this only works with your 1200 set into VGA mode. Most games won't work, but a surprising handful will, or can be promoted with a utility like modepro.
Cheapest option, least compatible.
2: RGB to VGA adapter plus monitor like ST2320 or similar. There's a handful of monitors (I have one from Dell) that do support amiga screen modes. You'll still need the above adapter.
3: External scan doubler. These vary in price and quality. I had one for some 100 dollars or so that was decent, if a bit unimpressive. Works with most any monitor though.
4: Indivision or similar. These go inside the amiga, and will let you connect to most any monitor as well.
Note that none of these options will be perfect, but they are mostly all quite usable. Indivision or a compatible monitor are the more expensive options but they will also give better results.
